The music record collection was donated by the honorary ambassador Christos Diamantopoulos and his wife, in the 1960s during the chairmanship of Kostas Nikolakis Mouchas. It numbers approximately 1,000 classical music records, which extend from Baroque music to Janni Christou and Iannis Xenakis.

The Diamantopoulos collection comprises symphonies and chamber music. There are also some opera works by Weber, Wagner, etc.

The collection has historic value because of the rare performances and the recording of a transitional period from the 78 rpm to the 33 rpm and from the monophonic to the stereophonic sound system. They are rare because of their age and material. Despite the passage of time, they preserve in their recording this characteristic vinyl sound quality, typical in monophonic records as well.